EHT Inductive Adder for Nanosecond-Scale High Voltage Pulses into Low-Impedance Loads

EHT inductive adders allow high voltage pulses into 50 Ohm loads with rise times on the nanosecond-scale. This topology has the following benefits:

All drive components are ground-referenced. This eliminates switching jitter problems, and floating gate drive complexities.
Agility of pw (pulse width) and prf (pulse repetition frequency). The output pulses are defined by input pulses to gates.
Identical modules all switch same voltage and current are triggered simultaneously, i.e. a modular design.
More modules allows scaling to higher voltages.
A wide range of loads can be driven.
Load and load voltage are almost completely independent.

Case study, Office of Naval Research (ONR): the intent is to drive non-linear transmission lines (NLTLs) producing high power microwaves. 35 kV pulses were produced with adjustable pulse widths (40-100 ns) and fast rise times (11 ns). Short bursts were demonstrated at prf up to 1 Mhz.

EHT Inductive Adder Waveform showing 40 ns pulse widths with 11 ns rise time for 35 kV output pulses into 50 Ohm (700 A) load. — Inductive Adder waveform: 40 ns pulse widths with 11 ns rise time, 35 kV output pulses into 50 load (700 A).

EHT Inductive Adder Waveform for 35 kV output pulses into 50 Ohm showing 100 ns pulse widths with 11 ns rise time. — Inductive Adder waveform: 100 ns pulse widths with 11 ns rise time, 35 kV output pulses into 50 load (700 A).

A next-generation unit will achieve the following specs:

Input power: 15 kW DC supply
Energy per pulse: 1.8 J at 30 kV
Adjustable output pulse width: 25-100 ns
Output voltage: At least 30 kV into a 50 Ω load
Output rise time: 12 ns or less
PRF at 12 kW and 100 ns PW: 6 kHz
PRF at 12 kW at 25 ns PW: 25 kHz
Duty cycle: pulser will operate at least 2 seconds continuously, once every 2 minutes

Applications for inductive adders:

Radar
High power microwave
Klystron driving
Stripline kickers
Pickups for accelerators

EHT Inductive Adder with modular system design produced 40-100 ns pulses with fast 11 ns rise-times and 35 kV power. — EHT Inductive Adder: 35 kV pulses with 40-100 ns pulse widths and fast 11 ns rise times.

Inductive Adder modular design from Eagle Harbor Technologies allows scaling to higher voltages equipped with wide range of loads. — EHT Inductive Adder: modular design allows scaling to higher voltages.